It's not 'TIL. It's TILL.
GO AHEAD, I WILL WAIT RIGHT HERE WHILE YOU LOOK IT UP.
I've fought nearly every editor I've ever had on this. I know, I know, the spelling of words changes with the times, and maybe my side will lose this battle. But I must try, for I dislike introducing punctuation into words when it isn't necessary. And don't give me that argument about how "till" also means (verb) "plow the land" or (noun) "cash register," because those are never going to be confused with a preposition in daily usage.
In the meantime...
If TILL was good enough for C.S. Lewis, it's good enough for you.
Oh yes, I'm ornery today. Look out. (But, all the same, happy holidays!)